Turbodrive and control



July 29, 1941. H. o. scHJouN TURBODRIVE AND. CONTROL Original Filed Feb.9, 1938 5 Sheets-sheaf 1 July29, 1941. v H. O.'SCHJO'LIN I 2,250,656

TURBODRIVE AND CONTROL Original Filed Feb. 9, 1938 5 Sheets-Sheet 2 y1941. H. o. SCHJOLIN 2,

TURBODRIVE AND CONTRQL Original Filed Feb. 9, 1938 5 Sheeis-Sheet 41941- H. O.'SC HJO L|N 2,250,656 I TURBODRIVE AND CONTROL 7 OriginalFiled Fb. 9," 1938 5 sheets-sh' ei 5 Pat ented July 29, 1941 TURBODRIVEAND CONTROL Hans O. Schjolin, Pontiac, Mich., assignor to Yellow Truck &Coach Manufacturing Company, Pontiac, Mich., a corporation of MaineOriginal application February 9, 1938, Serial No. 189,596. Divided andthis application August 2 1940, Serial No. 354,310

4 Claims.

The invention relates to motor vehicles, and more particularly to animproved compact group-v ing of the driving mechanism for large, heavyvehicles, such as buses, trucks and tractors, as shown in my applicationS. N. 189,596, filed February 9, 1938, of which the present applicationis a division.

In passenger buses in particular it is essential to .arrange the drivemechanism in a space which shall detract the least from the pay loadspace, and while vehicles having transversely mounted power plants atthe rear are known in the. art, the present invention-embodies aspecific, improved arrangement, which, while including structures forthe most part in general use and of conventional character, myarrangement imparts the drive to the vehicle wheels through a systemwhich provides the least wastage of effort in power conversion from atransversely driving and torque converting assembly, in that the finaloutput shaft receives its drive from the main centerline of the primarydrive assembly.

A further novelty herein is the adaptation of the turbine form oftorque-converter to the above noted form of drive, so that there is theleast wastage of axial space consumed by the primary power group; theadded utility of providing for accessibility for replacement andassembly of the groups, and the novel nature of the power plantcombination which provides adequate accessory unit drive at the end ofthe primary power group remote from the engine.

Further objects in the application of operatoroperated interlockingcontrols for the above forms of driving mechanism are achieved herewith,in the prevention of wrong motion, and-in the coordination of foot andhand operated elements, wherein the said interlocking means areconnected with fluid pressure servo devices to accomplish the shifts ofdrive between direct and converter positions.

Additional objects and advantages will appear Figure2 on line 33, withshifter engaged.

Figure 4 is an enlarged view of the direct drive clutch D of Figure.2. v

Figure 5 is an elevation-section view of a friction clutch used as amodification of the direct drive clutch of Figures 2' and 4, andidentical in construction with the friction clutch C of Figure 2.

Figure 6 is an operationfdiagram, schematic insofar as the generalarrangement of the control elements are concerned, but giving theoperators hand and foot operated controls in ele vation and partsection. v

Figure 7 is a longitudinal section of the servo control valving ofFigure 6.

Figure 8 describes in detail the interlocking arrangement of Figure 6between the hand control and the pedal control, and is a view takengenerally at 8-8 of Figure 6.

Referring particularly to Figure 1, it will be seen that my arrangementis shown as installed in the rear of a bus, with the primary power plantarranged transversely, and the output drive 'in the fore-and-aft planeof the vehicle, connecting by a short jackshaft to the conventionaldifferential gear and axle drive to the rear 'wheels.

The primary power plant comprises an engine A of suitable type, a clutchC, a clutch D, a turbine type torque-converter T as a variable speedtransmission, a gear assembly R, an overrunning device F, and anaccessory drive mechanism E, all mutually coaxial.

The propeller shaft extends forwardly with respect to the vehicle, anddownwardly, from a point intermediate the engine A and thetorqueconverter unit T, connecting to the conventional differentialgear, as noted.

In Figure 2 the engine crankshaft is shown at l, mounted'to rotate driveshaft 2 splined at 3 for slider 4, and splined at 5 for hub- 6 andflange fitting 8. v

Sleeve 9 mounted on bearings, surrounds shaft 2 and is attached to orintegral with member III,

which has internal ring of teeth II and external bevel teeth l2.

The teeth l3 of slider 4 mesh with H, whereupon member I0 is 'driv en atengine speed.

Output jackshaft 60 rotating in bearings 6| in casing 20 is fixed to orintegral with bevel gear 14 meshing with gear 12, transmitting the driveof sleeve 9 to the driving wheels of the vehicle, as shown in Figure 1.

Sleeve I5 concentric with sleeve 9 is bearing mounted on shaft- 2 andhas aflixed gear l6 and roller clutch race l8, its inner ,endterminating in turbine element 30, which is the output member of theturbo torque-converter T. The outer roller clutch member 2| isexternally splined at 22, and teeth 23 and spline 24 of sleeve 9 arealigned axially and radially therewith. Bridging slider 25 is splinedinternally at 2| so that when these teeth are in mesh with the teeth 23of sleeve 9, the outer member 2| of the roller clutch assembly F isreleased. External teeth 26 of slider 25 are arranged to mesh also inthe leftward position with the teeth 28 of gearbody 29 rotating inappropriate bearings in casing 20. Teeth 21 of gearbody 29 constantlymesh with reverse idler gear 32, which in turn mesh with gear Hi. Whenslider 25 is in the right hand position of the figure, the drive frommember IS. The rollers are biased by appropriate means, for one-waylocking ofmembers l8 and 2|. The cage |9a has limited lost motion withrespect to member l8.

The neutral position of the slider 25 occurs when the teeth 2|- aredemeshed from spline teeth 22 ofelement 2|, partially meshed with teeth23; but without mesh between teeth 2628.

The detail of one form of clutch D is shown in Figure 4 where slider 4splined at 3 to shaft 2 may mesh its teeth I 3 with teeth H of bevelgearbody l0. Inside the overhang of teeth H is sleeve I5 is throughroller clutch members 18 and 2| to slider 25,' since internal splines 2|are then meshed with teeth 22 and thence from slider 25 to sleeve 9,yielding forward" drive. When the slider 25 is in the left handposition, the drive is through gears |532, gearbody 29, slider 25 andsleeve 9 through the described toothed elements, yielding reverse drive,which is obvious from the pairing of the gearing.

The hub 6 is one member of the turbine driving clutch C,.and hub 33 isthe other, splined on sleeve 34, integral with the input or impellermember 40 of the torque converter T.

The blades 50a, and 50b are integral with reaction member 50 attachedto, or integral -with casing 20.

The rotation of impeller 40 causes the liquid contained in the casing toimpinge on the blades 3|a against which the liquid is thrown bycentrifugal force from buckets 4| of the impeller 40. The specializedcontour of the blades 50a and 50b permits the liquid to apply arotational force tobutput-connected blades 3| and 3|a mounted in rotor30 attached to sleeve i5.

The multiplication of torque achieved in the turbine by virtue of thepresence of the reaction members 50a and 50b is ,a well-known effect,

described in U. S. 1,199,359 to Fottinger, filed.

June 19, 1906, issued September 26, 1916; and no invention is hereinclaimed for this characteristic.

It is deemed suflicient to state "that the three elements of the turbinedevice constitute a multiplier of torque imparting a variable speed tosleeve |5 from sleeve 34 rotating at engine speed.

When clutch C is engaged, the drive of the engine is transmitted tojackshaft 50 through the torque converter T at variable torques andspeeds.

When clutch D is engaged, the drive is transmitted at a fixed ratio fromengine shaft to iackshaft 50; whereupon both members, input sleeve 34and output sleeve l5, of .the torque converter T may come to rest, sinceroller clutch F permits sleeve 9 to overrun sleeve l5.

The detail of roller clutch F is shown in Figure 3, and since this typeof structure is well known, no lengthy description of its operation isbelieved necessary inthe demonstration of my invention. It is worthy ofnote that the arrangement of the outer member 2|, inner member l9,sleeve l5, and slider 25 constitutes a means for obtaining a fullrelease of the roller clutch F when the slider 25 is placed in thereverse position. The arrangement permits the saving of power plantlength by mounting the transfer control for forward, reverse and neutraldrive between the toothed ends of the gearbody 29.

of slider 4, for limited rotational motion with respect to slider 4.Auxiliary teeth 540-55 cut on slider 4 are spaced to accommodate poppets58,

-'which areloaded radially by springs 59 in the radial recesses shown.The poppets 58 transmit axial force on slider 4 toward mesh of teeth |3|to the adjaoentedge of spline teeth 54a of balk piece 53, sothatregistry of the teeth of 5455 will coincide with release of dragforce, permitting |-3| to mesh without clash. Additional force is neededto depress the poppets for completion of mesh.

Piece 53, because of friction contact of its rin 56 with ring 52 at 52a,may then rock positively or negatively on the splines 54, so that teeth54a of piece 53 will be out of registry with teeth 55, the teeth endsabutting, preventing further motion toward mesh of slider 4 and teethl3.

If the faster member be the engine shaft the balking piece 53 willrotate positively due to friction drag, to set up rejection of'mesh. -Ifoutput connected member Ill be the faster member, in either case thereis rejection of mesh until the drag' force acting on piece 53disappears, as

it does at synchronism, when the slider 4 may now move, teeth 55 mayenter spline teeth 54a of piece 53, and also teeth |3 mesh with teethwhereupon direct drive between shaft and'member I0 is accomplished.

During the asynchronous rotation interval of slider 4 and member Hi, theopposing force condition persists, until synchronism is reached. Thenthe drag force from ring 52 to ring 56 disappears, which because of therelease of the balking action, permits further free travel toward mesh,thereby allowing teeth |3|| to complete meshing engagement.

This is described as a form of synchronism responsive mechanism having abalking, or rejection-of-mesh characteristic, wherein the friction andcamming forces are provided to control the mesh motion rather than toabsorb the difierential inertias of the engine and vehicle. Thecharacteristic may be described as a friction balklng or lock-out actionarranged to-permit mesh or reject mesh, according to synchronous orasynchronous rotations of the two members to be The inner face of theouter member 2| is smooth, and acts as. a race for rollers I9 .carriedin cage |9a rotating with the inner one-way cam connected for unitaryrotation.

it should be emphasized that if the driver alpresion of the acceleratorpedal, whereupon, as

before, the completion of mesh is permitted.

hub 33 and may engage projection 31 of presser' plate 36. The innerportion of spring 42 engages sleeve 45 movable longitudinally so as toshift the inner part of the spring 42 to either side of its criticalflexion position with respect to the clamped outer edge.

When the sleeve 45 is positioned to the right, as in Figure 2, theexternal force applied to sleeve 45 shifts spring 42 throughits criticalflexure position, whereupon the force of the spring is exerted onprojection 31, tending to load presser plate 36. Hub 33 carries thedriven element 49 of clutch C to which the customary facing discs 48 areaffixed. When plate 36.is loaded, clutch C transmits the drive of shaft2 to the input member 40 of the torque converter T, at a given clutchcapacity.

When the external force shifts sleeve 45 to the left, the spring 42 isanew flexed through the critical position, and its force is dissipatedin holding the presser plate 36'free from load, thus declutchingclutch-C.

It should be noted that the external force to be applied to sleeve 45need only be effective to carry the spring 42 through the criticalmidposition, and that no external force thereafter is needed to hold theclutch C engaged or disengaged.

External controls for clutches C and D, alternating their engagement,may therefore connect the drive for variable speed and torque throughthe converter un'it'T, or for fixed ratio or direct drive.

In Figure 5 the clutch assembly D takes the form of a friction clutch,identical in operation with that of the clutch just above described, andshown as connecting shaft 2 and sleeve 9. The prime-numbered elements ofFigure 5 correspond to the parts described above in conjunction with theturbine driving clutch C of Figure 2.

Referring back to Figure 2, the collar of slider 4 is intersected byfork I aflixed to rod II having sliding bearing in casing extensions 12and 12a. Lock ring 73 retains biasing spring 14 which normally urgesslider 4 toward engagement of teeth I3II. Rocker lever I pivoted on thecasing is arranged to load the slider 4 for disengagement through pistonrod 16 and Diston I26 of air cylinder I25 mounted on the casing 20 whenair is admitted to pipe I 22, to overcome the tension of return spring".

At the right of Figure 2, the casing 20 is shown broken away to disclosethe external control applied to collar 44 which moves clutch sleeve 45splined on casing extension 46, Fork 4! pivoted to the casing 20'ismoved by its external lever 41a pivoted to piston rod I32 attached topiston I3I of cylinder I30 mounted on the casing 20. When air isadmit-ted to pipe I23 and cylinder I30, collar 44 and sleeve 45 aremoved toward the left. When air pressure is released therefrom, returnspring I33 in cylinder I30 shifts collar 44 and sleeve 45 to the right.The servo actuation means are shown schematically, and

may be. so disposed in the engine compartment space as engineeringrequirements demand. The detail of the servo control system is givenfurther in this specification.

The prime-numbered elements in the lower half of Figure 5 refer toidentical parts in the control for clutch D of Figure 4, the arrangementfor Figure 5 being identical with that for clutch C of Figure 2.

Figure 6 describes the remote control system for clutches C and D,whereby the operator may at will select and operate the drive throughthe torque converter, or in direct.

The driver controls consist of a gearshift lever assembly I00 mounted-torock longitudinally between three positions, forward, neutral andreverse; and pedal IOI having three operative, positions; direct foractuation of clutch D, neutral,

and the fully depressed position for putting in clutch C which drivesthe torque converter T.

The system of the demonstration includes air servo means consisting ofreservoir I02, maindetail in Figure 7, having external lever H5 and linkIIB moved by lever IIB of pedal IOI. -When the pedal ml is. depressed tothe torque converter'position indicated, lever II8 swings clockwise fromthe position shown; and valve assemblies H0 and I20 admit atmosphere tolines I22-I23 and to cylinders'l25l30 in which pistons I26 and I3Islide. As will be seen later, the spring I33 of Figure 2 tends to engageclutch C, establishing drive through the converter T.

When pedal IOI returns to the neutral position shown, valve assembly I20 cuts off the atmosphere from line I23, and applies pressure tocylinder I30 so that clutch C is now disengaged,

flexing spring 42 to the left side of its critical position.

Movement of the pedal IM to the direct drive position rocks levers I I8and II 5 counterclockwise, so that both valve assemblies 0 and I20 admitair pressure from line I08 to lines I22-I 23 and to cylinders I 25I30;Piston I26 is arranged to permit spring 14 to load the slider 4 ofFigure 2 toward engagement; or to shift the sleeve 45' of Figure 5toward clutching engagement. Piston I 3| maintains pressure on spring I33, but spring 42 being flexed to the left of its critical position isnot thereby loaded.

When pedal IOI returns to the neutral position shown, valve assembly II0 cuts ofithe air pressure from line I05 and vents cylinder I 25 andline I22 to atmosphere, so that-clutch D may be disengaged, through therelieving of load a on spring I4 in the instance of the jaw clutchslider of Figure 1; or the action of spring 11', in

the case of the modification of Figure 5.

The shifter lever member is pivoted in fitting 9I fastened to thefioorof the drivers compartment, and its extension lever 90a is pivotedto rod 92 extending to the rear of the vehicle, to

bellcrank 93 mounted on the bulkhead I80. The other 'end of bellcrank 93is pivoted to rod 94 movable parallel to the bulkhead; the rod 94 being'in turn pivoted to rocking lever 95 pivoted on the casing 28 of thepower plant. The op-' posite end of lever 95 projects into the casing 28and is forked to operate the slider 25 of Figure 2. v

Tracing out the motion, one will observe that the lever assembly I88rocked counterclockwise exerts a pull on rod 92, rocking bellcrank 93clockwise, and through rod 94, rocking lever 95 clockwise. The forkedend of lever 95 then has shifted slider 25 of Figure 2 to reversedriving position. When the lever I88 is rocked clockwise, rod 92receives a thrust, and bellcrank 93 and lever 95 rock counterclockwise;which, upon comparison with Figure 2, causes slider 25 to uncouple thereverse driving gearing 23-2 8-2 'II 6,

and reconnect sleeve 9 with member 2I-25. ,Since it is desirable thatthe operator be enabled to compel not only a neutral position of slider25 but also a neutral drive for both clutches C and D, the .lever I88 isof composite form, being normally held in an extended position from thepivot 96 of fitting 9|, by spring 91 enclosed in sleeve 98.

ing the neutral pedal position at right angles.-

Each leg of the yoke 86 is equipped with a roller 8611 so that when theyoke '86 is pressed upward, the pedal I8I will be positioned at neutral,whether it has been in direct or in the torque converter controlpositions.

Bellcrank '88 is linked to bellcrank 81 by the short rod 88, and 81terminates in a cam foot 810 which intersects the motion of the rod endof yoke 86. Spring 89 bears against the floorboard fitting 84 andagainst cam foot 81a so that, normally, the pedal is free to movewithout interference by the bellcrank 81.

conical spring I5I which normally acts to cause valve I45 and roller I46to follow cam I68.

Tapered seat I52 at valve I48 may be sealed by the adjacent end of thedumbbell valve I at full stroke.

Servo port I41 connects to line I22, and to cylinder I25 of the directdrive clutch D.

When'the valve I45 is as shown-in Figure 7, spring I5I is active, camI68 is out of the way, air pressure in line I85 seals port I43 withdumbell valve -I4I assisted by spring I42, and the 'servo line I22 andcylinder I25 are vented through port I41,'passage I48, port I49 and portI58.

When cam I68 stresses spring I5I, shifting valve I45 to the left, portI49 is out of registry with port I58, and ground seat I52 intersectsvalve I4I, unseating it, and admitting air pressure from line I85 andnipple I48 to port I41 and line I22. As has been noted, this positioncorresponds to the shift from neutral to direct drive of pedal I8I,which through the linkage II8--II6II5, rocks shaft I6I and cam I68, tomove roller I46 and valve I45.

Similarly, in description of valve assembly I28, valve I55 in bore II2of easing I89 is equipped with roller I56, has central port I58communicating with port I59 and carries ground seat I62 held by conicalspring I63. Dumbell valve I64 is normally loaded by spring I65 to sealpressure port I66 connected to nipple I61 of line I23, and is unseatedat full stroke of valve I 55. Atmospheric port I68 in casing I89 mayintersect port I59 oi. valve I55; and vent servo port I61, line I23 andcylinder I38 of the torque converter clutch C.

Whenever the driver depresses the knob 99a and rod 99 to compress spring91, the above described bellcrank system becomes active, spring 89 isalso stressed, so that unless the pedal IN is already in the neutralposition, the resulting Figure 7 provides a sectional detail describinga specific form of valve mechanism used herewith as an example of theprinciples of the invention.

At the left the valve casing I89 is equipped with nipple I48 joined topipe I85 leading from the pressure source. Dumbbell valve I held bysmall spring I42 normally seals port I43 in casing I89. g

In description of the valve assembly II8, bore III is occupied by valvebody I45 having pivoted roller I46 at its right end. The valve I45 iscentrally drilled at I48 and communicates with annular port I49 whichmay intersect atmospheric port I58 cut in casing I89. The hardened seatI52 is held on the spindle end of valve I45 by When the valve I55 is asshown in Figure 7, the cam I68 is active, spring I65 is compressed.ground seat I62 has, intersected the dumbell valve I64 sealing oil thecentral passage I58, opening pressure porting I86 to the servo line I23,

and the annular port I59 has shifted out of regwhen it is in the directdrive position, both valves I45 and I55 admit reservoir pressure to bothcylinders. I25 and I38.

In the case of the modification of Figure 5 where the jaw clutch ofFigure 4 is replaced by the friction clutch for direct drive, the sleeve45, which stresses spring 42', is arranged so that when servo pressurein cylinder I25 is exerted, the spring 42 is positioned to flexibly loadprojection 31' of pressure plate 36'. When the air pressure is relieved,spring 11' may overcome the force of 42 and disengagethe clutch D.

When the operator is driving the vehicle in direct drive, the airpressure is therefore maintaining the sleeve 45 of the clutch J) in enaged position, and clutch C is disengaged. If there be a demand foracceleration at a lower speed ratio than 1 to 1, the operator willdepress pedal III to -torque converter" position. Valve I45 first cutsoif the servo pressure from cylinder I26, as the pedal I8I passesthrough neutral position; and spring 42 being shifted by spring I33,flexes away from the presserplate 36",jand clutch D becomes disengaged.

When the pedal reaches the torque converter position, valve I55 moves tocut oil servo pressure from cylinder I30, which vents to atmosphere, andspring 42 of clutch C is shifted so as to load the presser plate 36, andthereby establish drive through the clutch plate and the torqueconverter T of Figure 2.

The relative biasng shown for the clutches for engagement anddisengagement is believed to be novel, providing advantages in smoothoperation, safety, and the ability to maintain operation regardless offailure.

Further modification may be made of the relative action of the clutchcontrol members with respect to the inherent characteristics of the discspring actuating clutch controls, without departing from the scope of myinvention.

In order to assure the shifter mechanism moved by the operators control99 fromwrongmotion, the shifter mechanism is interlocked, so that theball 99a and rod 99 must be depressed for each shift among forward,neutral or reverse.

The sectional view of Figure 8 shows lever 90a movable with the rockingshifter motion of rod 99 as shown by the arrows. On the inner face oflever 90a is welded guide key I10. Pad 82 of lever 80 moves in an arc tointersect key I10, and

notches l'llR, "IN, and l'llF respectively, are

the positions occupied by the tongue of the key I'Ifl when the handleverassembly I is placed in- .the reverse, neutral and forward positions.

The lever assembly I 00 cannot be rocked through these positions untilgearshift ball 99a and rod 99 are depressed sufliciently to swing lever80 and the notches of pad 82 clear of the key I10.

When the new shift is accomplished, the spring cluding a hollow shafteddriven member, a sleeve member for power take off from the transmissionmounted in axial alignment with the hollow shaft part of said drivenmember, a releasable coupling for selectively transmitting powerdirectly from said driven member to the adjacent end portion of saidsleeve member, gearing including an axially shiftable gear forselectively transmitting power in reverse direction from said drivenmember to the adjacent. end portion of said sleeve member, and meansincluding a high speed drive shaft extending through said driven memberand said sleeve member, for transmitting drive to the end portion of thesleeve member remote from said driven member.

2. In a power transmission having a high speed drive and avariable-speed low speed drive inv driven member to the adjacentend'portion of 89 returns the lever 80, pad 82 and notches to lockingposition. This simple interlock is believed an improvement over thecustomary poppet locking means.

cluding a hollow shafted driven member, a sleeve member for power takeoff from the transmission mounted in axial alignment with the hollowshaft I part of said driven member, means comprising an overrunningclutch and a releasable coupling for selectively transmitting drive inone direction said sleeve member, and means including a high speed driveshaft extending through said driven member and said sleeve member forselectively transmitting drive to the end portion of the sleeve memberremote from said driven member;

ber, means for selectively delivering power through said high speeddrive to the power take- 'oif member, means including an overrunning Thepreceding description is believed to encom- From the foregoing, it isapparent that a num her of related novelties embodying invention incombination are herewith disclosed. Changes in the specific arrangementsand forms of the struc-- tures may .be made without departing from thespirit and scope of my invention, said invention being limited only bythe scope of the appended claims.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patcut is:

1. In a power transmission having a high speed drive and avariable-speed low speed drive inclutch for transmitting drive in onedirection only from said driven member to the power takeoff member, andmeans including an axially shiftable gear for selectively transmittingdrive in reverse direction from said driven member to said powertake-off member independently of said overrunning clutch.

4. In a variable speed transmission, hydraulic power transmittingmechanism including a hollow'shafted turbine member adapted to be drivenin one direction only, a power shaft extending through said turbinemember for effecting drive in the same direction in alternation with thedrive transmitted through said turbin member, a driven member, anoverrunning clutch for transmitting drive in one direction only fromsaid turbine member to said dnven member, and mechanical reverse gearmechanism associated with said turbine member including a driving gearon said hollow shaft part for transmitting drive from said turbinemember to said driven member in opposite direction to that in whichdrive is transmitted by said overruning clutch.

ms 0. sensor-m.

